Surgical device for connecting soft tissue

ABSTRACT

The invention comprises a surgical instrument including an external tube ( 2 ) and two elongated members ( 4 ) positioned in said tube ( 2 ), each of which includes a distal end ( 10   a ) for capturing one of the two tissue zones (M 1 , M 2 ) to be attached. The instrument ( 1 ) may further comprise a catching member ( 22, 25 ) for each tissue (M 1 , M 2 ) to be attached; a rod ( 15, 16 ) linked to each catching member ( 22, 25 ) enabling tension to move axially, said rod ( 15, 16 ) being separable from said catching member ( 22, 25 ) when a tension is exerted on it beyond a certain threshold; and a member ( 17   a ) forming a stop for locking axially each catching member ( 22, 25 ) during said tension.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.10/877,279 (Attorney Docket No. 020489-000330 US), filed on Jun. 24,2004, which was a divisional of U.S. patent application Ser. No.10/202,599 (Attorney Docket No. 020489-000310US), filed Jul. 24, 2002,now U.S. Pat. No. 6,770,083, which was a divisional of U.S. patentapplication Ser. No. 09/523,018 (Attorney Docket No. 020489-000300),filed Mar. 10, 2000, now U.S. Pat. No. 6,461,366, which was acontinuation of PCT/FR98/01960, which designated the United States,filed Sep. 12, 1997, the full disclosure of which is incorporated hereinby reference.

BACKGROUND OF THE INVENTION

This invention provides a surgical device allowing the percutaneousconnection of two soft tissue areas that are ordinarily separate. Thisdevice is particularly intended for reconstruction of heart valves,especially the mitral valve, and for the treatment of any malformationof a heart septum.

In a condition known as mitral insufficiency, the mitral valve does notcompletely shut, and does not prevent the back-flow of blood to the leftatrium from the left ventricle. Surgical repair is then necessary. In acurrent procedure, a sternotomy is performed. The patient is then placedunder extra-corporal blood circulation while the heart is stopped, andthe heart chambers are opened to gain access to the mitral valve,usually through the left atrium. Once the mitral valve is accessed,repair procedures include annuloplasty and, more recently, suturing ofthe free edge of the anterior leaflet to the free edge of the backleaflet where the mitral insufficiency occurs.

These procedures are complicated and require general anesthesia,sternotomy and extra-corporal blood circulation. They also require highdoses of anti-coagulant therapy adding to the operative risk of amyocardial infarction and hemorrhage.

SUMMARY OF THE INVENTION

The methods of the present invention are performed percutaneously,diminishing considerably these risks. A surgical device allows theconnection of two zones of soft tissue that are usually separate. In aparticular embodiment, a connection is formed between a free edge areaof an anterior mitral leaflet and a free edge area of a back mitralleaflet. Suitable surgical devices for performing tissue connection aredescribed for example in EP 558 031 and WO 94/18893, and may comprise:

(a) a tube which may be inserted percutaneously until its distalextremity reaches the area around the tissues to be connected; and

(b) two elongated elements inside that tube, each of which comprises adistal extremity having a device that grasps one of the two tissues tobe connected;

(c) wherein the distal extremities of these elongated elements may beopened and closed in order to permit introduction into the desired area,allow the procedure.

Particular devices according to the present invention may furthercomprise:

(a) a grasping element, optionally having two parts for capturing eachof the tissues to be connected, wherein the grasping or hooking elementeffects the connection of the two zones of tissue when brought closethereto by shifting of the portions of distal extremities to a positionwhere they meet;

(b) a rod connected to each of the grasping or hooking elements andoperated from the proximal end of the tube in order to axially shift theelongated element, wherein the rod can be separated from the grasping orhooking element upon pulling beyond a given threshold; and

(c) a wedge inside the tube, allowing the axial immobilization of eachgrasping or hooking element while pulling on them.

The rod positions the insertion of the hooking element up to the levelof the tissue edges to be connected. The rod also engages the hookingelement against the wedge in order to open the two hooking parts.

According to the present invention, the device may be used to remotelygrasp through a percutaneous passage, to draw together, and to connectthe two zones of tissue by a simple external manipulation.

Preferably, the tube, the elongated elements, and the rod are flexibleenough to be inserted percutaneously and through a patient's vasculaturefor the treatment of the leaflets of a cardiac valve, in particular themitral valve. Each of the elongated elements is made out of anelastically flexible material, and one of these elongated elementsdiverges from the longitudinal axis of the other. The two elongatedelements can move axially in relation to the tube between (a) aretracted position within the tube where the ends of the elongatedelements are flexibly bent and closed together, and (b) a position wherethe ends of the elongated elements spring open and diverge from eachother in a way that permits those ends to capture the soft tissues inorder to grasp them.

The elongated elements may be deployed to allow their distal extremitiesto grasp the tissue areas or may be retracted in order to make theinsertion, shifting or removal of the apparatus easier. Each elongatedelement may comprise a rod made of elastic material, with a curveddistal extremity and/or a harpoon shape, and a sheath able to slideaxially in a forward position to cover the distal extremity and slideback to uncover it.

According to a variation, each elongated element can be composed of atube linked to a system that contracts its internal volume in order tograsp the corresponding tissue area, and expands to release the tissuewith no lesion. In this case, the wide-mouthed shape of the elongatedelement's distal extremity will insure a large enough grasping surface.

Preferably, the device includes two hooking elements. One is operated onthe distal side of the tissues, and the other, to be operated on theproximal side of the tissues, is situated between the first hookingelement and the wedge element. This way the two hooking elements can beoperated on both sides of the tissues and can be pressed together for aperfect attachment of those tissues.

BRIEF DESCRIPTION OF THE DRAWINGS

For greater clarity, the invention is described again in reference tothe enclosed Figures representing two unrestricted examples of theinvention in its optimal capacity.

FIG. 1 shows a longitudinal section of a heart with a mitral valve thatdoes not shut properly and has to be treated with this device.

FIG. 2 shows the mitral valve before treatment.

FIG. 3 shows a mitral valve similar to FIG. 2 after treatment by sutureaccording to the usual procedure.

FIG. 4 is a view similar to that of FIG. 1, with the device of thepresent invention inserted into a heart.

FIG. 5 is an enlarged view of a longitudinal section of the distalextremity of the device.

FIG. 6 shows a view of this distal extremity according to the line VI-VIof FIG. 5.

FIG. 7 and FIG. 8 are similar views to FIG. 5 at different stages of theprocedure.

FIG. 9 is a similar view to FIG. 2 of the mitral valve after treatmentwith the device.

FIG. 10 is a view of this valve according to line X-X of FIG. 9.

FIG. 11 illustrates an alternative embodiment of the device of thepresent invention.

DESCRIPTION OF THE SPECIFIC EMBODIMENTS

FIG. 1 shows a heart C with a mitral valve M having poorly opposedleaflets (M1, M2). Thus, the valve M does not shut tightly and no longerperforms its back-flow function between the left atrium O and the leftventricle V. According to conventional procedures, after sternotomy, thepatient is placed under extra-corporal blood circulation. The heart isstopped and the heart chambers are opened to directly reach to the valveM and stitch together the free opposite edges of both leaflets (M1, M2)as shown on FIGS. 2 and 3. Connecting leaflets M1 to M2 restores a goodattachment between them and restores the imperviousness of valve M.

FIGS. 4 to 5 show a device (1) according to the present invention whichenables the percutaneous connection of leaflet M1 to leaflet M2. Thisdevice (1) comprises an external tube (2), guidewire (3), two elongatedelements (4), and a clipping system (5). The apparatus is sufficientlyflexible to be percutaneously inserted into the heart C, through thepatient's vascular, e.g., the Vena Cava Ve and the intra-atrial septumS. Guidewire (3) is inserted through valve M and so the distal extremityof external tube (2) is located in the left atrium O, with its distalopening facing mitral valve M.

Each of the elongated elements (4) has a distal extremity (4 a) that isnormally curved to diverge outwardly. A rod (10) is made out of arelatively rigid but still elastic material, more particularly in metal,with a sheath (11) of synthetic material. The distal extremity (10 a) ofthe rod (10) is sharp and more or less harpoon-shaped. The sheath (11)fits on the rod (10) and can slide axially to a forward position (asshown on left side of FIG. 5) in order to cover the distal extremity ofthe rod, and can slide back (as shown on the right side of FIG. 5) inorder to uncover that same distal extremity (10 a). The elongatedelements (4) extend from the end of the tube (2). Because of this, theycan be shifted axially in relation to the tube (2) between a retractedposition where the extremities (10 a) close together (FIGS. 7 and 8) andan extended position where these same extremities (10 a) diverge fromeach other (FIG. 5). The clipping system (5) comprises three concentrictubular rods (15, 16, 17) that can be slidably introduced over theguidewire (3). Each rod can also slide axially in relation to theothers. The internal rod (15) is linked to a disk (20) through afrangible area (21). The rod and disk (15 and 20) are made of moldedsynthetic material. The disk (20) is axially pierced in order to let theguidewire (3) pass through, and carries a clip (22). Side prongs (22 a)of that clip extend from the proximal face (20 a) of the disk (20). Acentral portion (22 b) of the clip (22) having a central ring forreceiving the guidewire (3) is embedded into the material of the disk(24).

The intermediate rod (16) is also connected by a frangible area (23) toa disk (24) with two clips (25). Side prongs (25 a) of these clipsextend from the distal face (24 a) of this disk (24), and centralportions of the prongs are embedded into the material of the disk (24).On each side, the disk (24) has two diametrically opposed notches (26,FIG. 6) to allow the passage of the elongated elements (4). The externalrod (17) has an expanded distal extremity (17 a) which engages theproximal face of the disk (24). Each of these rods (15, 16, 17) can beextended beyond the proximal extremity of tube (2) so they can beshifted by the operator.

A handle or other structure for manipulating the rods (15, 16, 17) willusually be provided at a proximal end of the device. The handle willpermit deployment rod (15) while rod (17) is held in a desired positionin relation to tube (2), and then deployment rod (16), while rod (17) isalso held in the desired position in relation to tube (2).

In practice, under X-ray or echography control, the guidewire (3) isfirst inserted through Vena Cava Ve, the intra-atrial septum S, andmitral valve M. Then tube (2) and its internal parts are inserted intothe Vena Cava Ve and through the septum S until the distal extremity oftube (2) is directed at mitral valve M (FIG. 4). At this stage, disk(20) should be held at the opening of tube 2 (FIG. 5), while elongateelements (4) are retracted so that their distal extremities areretracted into slots (26).

When the distal extremity of tube (2) is in the proper position, rod(15) is shifted to advance disk (20) beyond leaflets M1 and M2 and intothe left ventricle V. Elongate elements (4) are then advanced to theirextended positions, as shown in FIG. 5. As the elongate elements (4) areadvanced, their distal extremities diverge. After the elements (4) areadvanced, distal extremities (10 a) of rods (10) are positioned close toleaflets (M1, M2). The sheaths (11) of elements (4) are then retractedin relation to the rods (10) in order to uncover the extremities (10 a),each of which can then pierce and capture the adjacent leaflet M1 or M2.Tube (2) is then advanced over the elongate elements (4), drawing thedistal extremities (4 a) closer, as shown on FIG. 7. This action drawsthe free edges of leaflets M1 and M2 together.

Rod (17) is advanced distally in relation to tube (2), and rod (15) ispulled proximally in relation to tube (2) in order to insert the prongs(22 a and 25 a) of clips (22 and 25) into the leaflets M1 and M2. Thetension on rod (15) forces the prongs (22 a and 25 a) against theopposed walls (20 a, 24 a) of the disks (20, 24) and breaks frangiblearea (21). This break gives the prongs of the clips enough freedom ofmovement to ensure a good connection between leaflets M1 and M2. Thesheaths (11) are then advanced distally in relation to the rods (10) toengage leaflets (M1, M2). This facilitates the extremities (10 a) of therods from the leaflets (M1, M2). Rod (16) is then pulled while holdingrod (17) in position to break frangible area (25). Leaflets (M1, M2)have thus been clipped to each other by their free edges, as shown inFIGS. 9 and 10.

FIG. 11 shows a variation of the apparatus where rods (10) and sheaths(11) have been replaced by two catheters (40) having trumpeted distalextremities (40 a). These catheters (40) project beyond the proximal endof tube (2) and may be attached to syringes that permit the creation ofnegative pressure. The grasping or releasing of leaflets (M1, M2) isthen achieved by controlling the internal pressure within catheters(40). The trumpeted ends (40 a) ensure a sufficient grip on leaflets(M1, M2). Those ends (40 a) are preferably sufficiently flexible enoughto bend slightly when they are drawn between the wall of tube (2) andtwo lateral slots (26) of disk (20). The other parts of this alternativedevice are the same as already described and bear the same recordnumbers.

It goes without saying that the invention is not limited to the aboveexample and is opened to different variations. For instance, theunstressed shape of the extremities (10 a) that hook the tissues couldbe of a curved J which is straightened when drawn into the sheaths (11).The elongated parts (4) and the connecting system could also be placedin separate tubes. The device (1) could be inserted arterially as wellas veinously.

1. A heart valve leaf fastener comprising two pairs of arms, each pairhaving a suitable size for fastening heart valve leaflets and said twopairs of arms capable of fastening two adjacent leaflets.
 2. A heartvalve leaflet fastener as in claim 1, further comprising at least onecentral core wherein said arms project from said core.
 3. A heart valveleaflet fastener as in claim 1, wherein said arms pierce the leaflets.4. A heart valve leaf fastener comprising two pairs of prongs, eachprong having a size suitable for fastening heart valve leaflets.
 5. Aheart valve leaf fastener as in claim 4, wherein each pair of prongsprojects from a disk.
 6. A heart valve leaf fastener as in claim 5,wherein the pairs of prongs engage and penetrate the atrial andventricular sides of the valve leaflets respectively as the disks arebrought together.